Project Summary/Abstract Recent evidence has demonstrated that up to 30% of children undergoing adenotonsillectomy (AT) for pediatric obstructive sleep apnea syndrome (OSAS) will have significant residual disease. Although most patients will experience some benefit from AT, the ability to reliably predict the outcome of AT for any individual patient has not been demonstrated. The candidate's long-term goal is to become a leading expert in developing and critically evaluating treatments for pediatric OSAS. To help achieve this goal, the candidate's specific training objectives for this career development award include 1) obtaining advanced biostatistics and outcomes research training, 2) gaining experience in developing and validating a predictive model of surgical outcomes, and 3) developing further clinical expertise in the diagnosis and treatment of pediatric OSAS. These training objectives will be achieved by pursuing advanced biostatistical coursework and training through the Oregon Clinical and Translational Research Institute (OCTRI) Scholars Program as well as clinical and research collaboration with the OHSU Sleep Disorders Program. The overall research objective of this proposal is to develop a comprehensive predictive model for the outcomes of AT for OSAS that includes anatomic and dynamic functional risk factors determined by sleep endoscopy. It is our central hypothesis that a composite predictive model that includes sleep endoscopy findings will accurately predict the outcome of AT and allow estimation of the likelihood of surgical success. The specific aims of this study are to 1) determine the associations between a validated sleep endoscopy rating scale and post AT outcomes, and 2) develop and validate a composite predictive model of the outcomes of AT incorporating sleep endoscopy ratings and other baseline factors. These aims will be achieved through a prospective cohort study of children aged 2-18 years who are undergoing AT for a diagnosis OSAS. Other inclusion criteria will include risk factors predisposing to residual OSAS after AT: obesity, severe preoperative OSAS, African American race, and age greater than 7 years. Patients will undergo sleep endoscopy prior to AT. Outcome measures include apnea-hypopnea index, generic and OSAS-specific quality of life, and validated caregiver ratings of executive function. A composite predictive model using presence of post-AT OSAS as the primary outcome variable will be developed and validated. Such a model will allow more accurate and reliable prognostication of AT outcomes and will help to inform the need for postoperative follow-up and possibly suggest strategies for further intervention.